U.S. Pat. No. 5,871,001 relates to an apparatus for delivery of anaesthetic gas to a patient. Said apparatus has a mask which overlies the patient's face around the mouth and face but which does not abut against the face. Supplied gas is conveyed to the mouth of the patient via a flow channel and a mouthpiece. A flow channel is also provided for exhalation. When the patient exhales, the exhalate flows into the exhalation flow channel via a valve. If the patient does not exhale through the mouthpiece but, e.g., through the nose into the interior of the mask, said exhalate also flows into the flow channel for exhalation.
Inhalation is a way which is getting more and more important for the administration of pharmaceuticals. To this end, apart from the use of new locally acting pharmaceuticals for the therapy of lung diseases, new therapeutic strategies are developed making use of the lung as aditus for systematically acting substances.
Possibly, toxic active ingredients have to be applied by inhalation. For instance, cytostatic drugs (e.g., cisplatinum) or cytocines may be administered to a patient with lung cancer. When toxic active ingredients are administered, it must always be ensured that the contamination danger of the environment or possibly present persons with these toxic active ingredients is ruled out or kept as low as possible. For instance, residues of the toxic active ingredients can be exhaled from the patient's lung during the exhalation process. These circumstances are not taken sufficiently into account by conventional inhalation apparatuses or said apparatuses are very uncomfortable.